1. You Hold a Grudge
People whose partners recover well from fights report higher relationship satisfaction, according to research published in the journal Psychological Science. Unfortunately, the reverse is also true: When you hold on to and keep bringing up past beef, even after the fight is supposedly resolved, your dude is going to be unhappy in the relationship.
Do This Instead: When you're having an argument, address only the specific problem at hand, and resist bringing up issues in the past or perceived patterns of behavior based on one or two unrelated incidents. To that end, avoid the words never or always, as in, "You never want to hang out with my friends," or "You always forget to take out the trash."
2. You Issue an Ultimatum
Fighting is never fun, but fighting dirty drives him totally coo-coo. Researchers from Baylor University found that the way a person perceives his partner's emotions during an argument impacts how he feels. Specifically, when he senses that you're trying to assert power (by being hostile, critical, blaming, or controlling), he takes it as a threat—which triggers major stress on his part. Delivering an ultimatum is the prime example of you trying to dominate the relationship: Do this, or I'll leave you. It leaves him feeling powerless...and furious.
Do This Instead: Explain how his actions affect you, rather than issuing an order. Say something along the lines of, "It makes me feel like you don't care about me when ______." Besides, wouldn't you rather he fix his mistakes because he wants to, rather than because he has to?
3. You Give Him the Silent Treatment
That same Baylor University study discovered that people get upset when their partners act distant and cold. Freezing him out makes him feel neglected, another source of stress.
Do This Instead: If you're the type of person who needs to clear her head before you have a serious talk, tell him straight up that you need a breather, give him a specific length of time (fifteen minutes, one day), and then promise that you'll discuss the situation at the end of that time.
4. You Bite His Head Off After a Long Day
Surprisingly, guys are a lot more vulnerable to relationship ups and downs than women are, according to a Wake Forest University study. Researchers believe it's because women have an outlet to express their concerns—we turn to our friends—whereas for guys, their significant other tends to be their primary source of intimate conversation. So when you're acting a little bit nutty, he has no one to turn to talk about it.
Do This Instead: Check yourself before you snap at him for something silly. Are you actually stressed out or annoyed for an unrelated reason, like work or friend drama, and just taking it out on him? It might seem like not a big deal, but when you let your feelings run wild, you may end up hurting him more than he lets on.
5. You Play It Too Cool
You already know that acting needy is a turn-off...but pulling away too much can also backfire. Recent research published in Psychological Science reveals that couples get rocky when one person's commitment level is different from the other's. While it's true that not returning his text for a day or two will pique his interest if you're still in the early dating stages, once you're in a committed relationship, it's just going to make his cortisol levels skyrocket.
Do This Instead: Ditch the games, especially after you're official. While it's definitely good to have your own life apart from him (weekly girls' night, spinning class, etc.), the only time it makes sense to purposely distance yourself is if he's pulling away a bit. In that case, creating some space ups a guy's interest; any other time, it just makes him feel anxious and confused.